Controlling the Flow: Shower valves play prime role in saving water
These days taking a long, hot, soothing shower is a guilty pleasure. But with showerheads equipped with valves that send a hot spray out at lower gallons per minute, we can all feel a little less selfish and indulgent. So, what roles do shower valves play in the water conservation effort?
“Shower valves save water by getting to temperature quickly and maintaining the temperature over the course of the shower,” says Jean-Jacques L’Henaff, vice president of design at LIXIL Water Technology Americas. This saves water by preventing the need for the bather to make temperature adjustments or to actually leave the shower during adjustments.
Shower valves with volume control can save water by allowing the user to turn the valve to control the amount and intensity of the flow from a gentle stream to full-force, says Jerry Capasso, the product manager at Moen. For example, Moen’s Moentrol and ExactTemp valves have the volume control feature enabling users to personalize their shower experience to their own unique preferences or needs.
Most shower valves are designed to perform with specific flow rates in a range of installation situations; including filling a tub, says Katie Hayes, senior product manager for Danze, Inc. and Gerber plumbing fixtures. “For this reason, most shower valves are not restricted to provide water savings; rather the showerhead itself is designed to limit the volume of water.”
The components that achieve the water savings are the diaphragm in the pressure balance valves and the thermostatic cartridges for the thermostatic valves, L’Henaff says. “The pressure balance valves maintain a standard flow by balancing the system on the incoming hot and cold water pressure; the thermostatic cartridge not only balances the pressure but maintains an exact temperature.”
The showerhead is the key component to achieving water savings, as the flow controller contained within the showerhead, hand shower or body spray allows the user to adjust the water flow as needed, Capasso suggests. “Additionally, having a pressure-compensating flow controller is the best method in providing a constant flow rate across the full range of pressures in plumbing system. All of Moen’s showering devices include a pressure compensating device, delivering a great shower experience to the user every time.”
“Water flow is controlled in various ways based on the internal structure of a showerhead,” Hayes says. “But, don’t worry. You can still have a great shower experience using a lower volume of water. Some showerheads, like Parma Five-Function from Danze, offer features like pressure manifold and air-injection technologies. These products are engineered to deliver water droplets that actually feel larger, and deliver great water pressure at lower flow rates so you can rinse that soap off quickly. This showerhead also offers a powerful massage function, where maximizing pressure is key.”
Calculating Water Savings
A standard showerhead has a flow rate of 2.5 gpm. By choosing a showerhead with a 1.5 gpm flow rate, a homeowner would save 40 percent more water, L’Henaff says. If each person in a family of four took a ten minute shower every day with a 1.5 gpm showerhead rather than a 2.5 gpm showerhead, they would reduce their water use by almost 15,000 gallons of water per year.
The EPA estimates that showering accounts for roughly 17 percent of household water consumption, Hayes says. “If all households in the U.S. installed a lower-flow showerhead, like a WaterSense certified head that performs at 2.0 gallons per minute rather than a standard 2.5 gpm, we could collectively save 260 billion gallons of water. The other benefit to reduced water consumption in the shower is that you use less hot water and less energy is spent heating that water so you can see savings in your water bill, as well as energy cost of water heating.”
Reduced flow rates contribute to overall water savings, Capasso agrees. “The industry standard flow rate for a showerhead is 2.5 gpm with a maximum at 80 pounds per square inch but there are other areas across the country that have reduced requirements. For example, California has a maximum flow rate of 2.0 gpm, and Miami’s Dade County has a maximum of 1.5 gpm.”
Builders and developers of both residential and commercial properties alike want reduced flow to obtain the United States Green Building Council’s Leadership in Energy and Environmental Design certification, Capasso says. LEED is a rating system devised to evaluate the environmental performance of a building and encourage market transformation towards sustainable design. “Moen offers a variety of shapes, styles and functions with flow rates ranging from 2.5 gpm to as low as 1.5 gpm. For example, a 2.0 showerhead gives 20-percent savings over a standard 2.5 gpm, 1.75 yields 30-percent savings and 1.5 gpm is a 40-percent savings.”
Water savings is dependent on lifestyle choices, as well, says Leslie Petch, senior product manager at Kohler. “Obviously, the straightforward computation that most people use is that moving from a 2.5 gpm showerhead to a 2.0 will save you 20 percent; but is only save you 20 percent if you spend the same amount of time in the shower as you did with 2.5. With those early eco-showers, people would spend three, four or five times as long in the shower because those showers were so bad that they couldn’t get the shampoo out of their hair. The recommendation is to always look for that WaterSense listing because it does at least give people a base level that there is a reasonable showerhead engine there.”
Because there is increased focus on wellness, and people are living longer, they are looking for more and different functions from their showers, Petch says. “That may run counter to water conservation, but digital valves can still reduce the amount of water wasted no matter how or how much the shower is used, if people are not running a bath as much, but using a shower for relaxation instead.”
Safety Is a Prime Concern
What are the most important safety features in shower valves? The most important safety feature with a shower valve is the ability to prevent shower shock, which typically happens when a sudden hot water spike occurs in your shower after someone flushes the toilet, Capasso asserts. Since the toilet valve is demanding a larger volume of cold water than what the shower valve is using, it takes away from the shower allowing more hot water to mix within the valve.
“The good thing is all shower valves sold today are required to prevent shower shock. This can be accomplished with either pressure balancing or a thermostatic element contained with the valves,” Capasso adds. “Moen’s Posi-Temp and Moentrol valves feature a pressure balancing spool, the ExactTemp valve includes thermostatic device to prevent shower shock. Another option is to have a temperature limit device, something the installer or the homeowner can set to limit the travel of the handle towards the hot setting, so there’s always some mix of cold and hot water.”
Thermal shock and scalding could have very serious human consequences, and there are standards in place for shower valve performance to protect consumers from these risks, Hayes says. “Both thermostatic and pressure-balance valves should meet these standards by either maintaining constant temperature, regardless of pressure change, or by more slowly changing temperature when there is a change in hot/cold water pressure. Look for ASME A112.18.1/CSA B125.1 or ASSE 1016 certification on shower valves as well as check-valves for cross-flow prevention in situations of sudden changes in either hot or cold water pressure.”
The hot limit stop in thermostatic mixing valves and pressure balance valves is a very important safety feature to help prevent scalding that can occur following changes in the force of the water supply, L’Henaff says. These valves can be set to limit the amount of hot water that is mixed with the cold water, a particularly important consideration in homes with children or older adults.
“Protection against scalding has been a regulation in America for many, many years,” Petch says. The more common technology in American has been the pressure balance valve, and you also have thermostatic valves, either mechanical or digital. Both basically provide the same level of thermal protection. If there is a sudden interruption in the cold water supply, both valves will shut off instantaneously to prevent you from being scalded.
“As you grow older, you become less sensitive to temperature on your skin, and it’s certainly a big issue in assisted living projects, where you want to give people a level of independence. That’s why we’re seeing a fairly steady interest in thermostatic valves that actually sense the water temperature, whereas a pressure-balance valve is simply sensing the pressure of hot and cold water. Obviously the big benefit with a thermostatic valve is the ability to set an actual temperature, and also limit the maximum temperature.”
In terms of water savings, less water is used because the user is not constantly adjusting the water mix to achieve a desired temperature level, Petch adds. “One of the bigger trends that we’re seeing is the move toward digital valves, replacing a mechanical valve with an electronic digital using a touch screen interface; you get away from the brassware in the shower entirely. The digital is cheaper to install than a mechanical valve, but some of the features you can get with the digital (Prompt) such as the prompt valves which has a warm-up feature. In the morning, rather than adjust the temperature by hand to where you think it will be ideal, with a digital you can run the hot water only up to temperature and once it’s up to temperature, it stops the water flow and beeps to indicate it’s ready.
"This article was originally posted on ww.reevesjournal.com."